Low-temperature specific heat of the Y1-xPrxBa2Cu3O7 system

GHAMATY, S.; LEE, B.W.; NEUMEIER, J.J.; NIEVA, G.; MAPLE, M.B.

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

American Physical Society

Año: 1991 vol. 43 p. 5430 - 5436

0163-1829

Low-temperature specific-heat C measurements as a function of temperature T between 0.5 and 30 K are reported for Y1-xPrxBa2Cu3O7 compounds with x=0, 0.2, 0.3, 0.4, 0.6, 0.8, and 1.0. The Pr contribution to the specific heat of all of the samples can be described as the sum of a Pr nuclear Schottky anomaly of the form CN(T)=AT-2, a linear term CL(T)=T, and a Pr magnetic anomaly. For compounds with x0.6, which are metallic and superconducting, the Pr magnetic specific-heat anomaly has the same temperature dependence as a Kondo anomaly. For the compounds with x0.8, which are insulating, the magnetic specific-heat anomaly is consistent with antiferromagnetic ordering of the Pr ions with Néel temperatures TN of 10.9 and 15.7 K for x=0.8 and 1.0, respectively. For T